Unexpected synthesis of 1,3,5-triarly-1,5-diketones from aryl ketones via di-enamine mechanism

An Increased Understanding of Enolate Additions under Mechanochemical Conditions

“…Some difficulty has been observed with the Michael addition of α,β-unsaturated aryl ketones because of the steric hindrance on both substrates and strong bases are often used with low yield formation. Alternative methods have been explored including metal catalysis [ 22 ], enamine catalysis [ 23 ], and promotion by barium hydride or barium alkoxides [ 24 ]. Therefore, mechanochemistry provides a simple method to gain access to these 1,5-diketones.…”

Microwave Assisted, Silica Gel Mediated, Solvent Free, Michael-Addition of Aryl Methyl Ketones with Chalcones for the Synthesis of 1,3,5-triarylpentane-1,5-diones

“…Several synthetic methods has been explored using a variety of toxic and expensive metal catalysts both acidic and basic such as lanthanides, Bi(NO3)3, Bi(OTf)3, Cu(BF4)2 and others [9][10][11][12][13][14]. The conjugate addition of aryl ketones to acetohydrazone of aromatic aldehyde with catalyst of 1,2-di-enamine is also an efficient approach [15] to develop the novel organic synthesis by eco-friendly technique accelerate organic synthesis [16][17][18][19]. Traditional approaches for the synthesize of 1,5-dicarbonyl compounds typically appeal the use of enolates with aryl/alkyl vinyl ketones through 1,4-addition [20][21].…”

Mechanism and rate constant of proline-catalysed asymmetric aldol reaction of acetone and p-nitrobenzaldehyde in solution medium: Density-functional theory computation

“…List’s NMR/GC-MS study [32] , Houk’s Density-Functional Theory (DFT) calculation [33] and several other studies that include both experimental and theoretical works were dedicated on finding new mechanistic insights into proline-catalysed aldolization using different combinations of aldehydes and ketones. However, most of these works relied on guessed transition states [34] , [35] , [36] . In the current study, we tried to adopt a more specific method of using quantum mechanical descriptors of Highest Occupied Molecular Orbital energy (E-HOMO) and Lowest Unoccupied Molecular Orbital energy (E-LUMO) to propose the transition states.…”